27

Poll_Endpt1

Returns:

Default:

Addressed:

Configured:

Notes:

bb xx yx yy zz

bb = button byte

xx = X motion byte

yx = XY motion byte

yy = Y motion byte

zz = Z motion byte (if Z-Wheel)

Ignore request

Ignore request

Accept (NAK if no data; Send packet if available)

See also Get_HID_Input. Endpt will only stall if halt bit is set by Set_Feature_Endpt1. Details of data

packet are below.

Endpt1 should be polled at least every 10 frames (mS). It is typically polled every 8 frames on Windows

machines. For internal testing, Endpt1 can be continuously polled if desired.

The chip will not generate any report packets unless in the Configured state.

If Endpt1 is currently empty, any motion or button change will be loaded into the Endpt1 buffers. Once

the Endpt1 buffers are full, any further motion events will get accumulated. When the Endpt1 buffers

are later polled and emptied, the current accumulated X/Y/Z values will be loaded into the Endpt1

buffers. After transferring their data, the accumulation registers are reset so they are ready to start ac-

cumulating new motion events.

Button information is handled a bit differently. If the Endpt1 buffers are empty, and a button change

event occurs, the new button state is put into the Endpt1 buffers. At the same time, the button state

that is put in Endpt1 is copied for later use. While Endpt1 is full, changes in button state are essentially

ignored. When Endpt1 is emptied, if the current button state is different than that which was last

loaded into Endpt1, then the new state will be loaded and a new copy saved. Basically, the button

state that is loaded into Endpt1 is always the current button state at that point in time. It should also

be noted that there is hardware on the chip to help de-bounce the buttons.

Special note on wLength:

The wLength paramater in commands specifies the maximum number of bytes a device should send

back. The commands listed below are not able to handle a wLength of 0 correctly.

Get_Status_Device

Get_Status_Interface

Get_Status_Endpt0

Get_Status_Endpt1

Get_Configuration

Get_Interface

This chip will send one byte of data rather than none when wLength = 0 is requested for the above

commands.

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PixArt Imaging Inc.

PixArt Imaging Inc.

ADNS-2710 Single Chip USB Optical Mouse Sensor